Grinding-barrel.



D. 0. DfiMARBsT.

GRINDING BARREL.

APPLICATION FILED upvqm, 190s.

Patentefi .Sept. 13, 1910.

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WITNESSES:

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lllll lllll) %'l rlflll l Pf lllhlll DAVID C. DEMAREST; OF SAN FRANCISCO. CALIFORNIA.

GRINDING-BARREL.

Specification of Letters Patent.

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Application filed November 16. 190%. Serial No. 462,890.

To all whom it may concern:

Be it known that 1, DAVID C. Dmmnnsr, citizen of the United States, residing in the city and county of San Francisco and State of California, have invented new and useful Improvements in. Grinding Barrels, of Which the following is a specification.

My invention relates to improvements in that class of grinding mills Which. are designed for the fine pulverizing of ores containing valuable mineral, so that such ores will be in the best possible condition for cyaniding, or other processes by Which'the gold and valuable metal is eventually separated from the worthless material.

-My invention consists in the combination of parts, and in details of construction which will more fully explained by rel.- erence to the accompanying drawings, in which- Figure 1 is an end elevation artly in see tion. Fig. 2 is a plan view partlyin section. l1 ig. 3 is an end elevation of a grind lug plate. ,Fig. at is side elevation of a grinding plate.

' In that class of grinding apparatus known as grinding barrels, or technically as tuhe mills, ore is delivered into the horizontally revolving cylinder, and by means of gravel, rock, or other material which is introduosd with the pulp, the latter is pulverized to the desirel degree of fineness, being delivered from the barrel through suitable scree s. Such devices, Where much gravel or metal ballast are used, provide only cor-nparatively small points of contact, and it requires a much longer time to pnoperly pulverize and reduce the ore than if larger surfaces, of contaotcould be utilized. lnmy invention I form such surfaces by the use of plates having a curvature such that they will substantially lit the interior curvature of the barrel, and such length that they will practically cover the lower inner surface of the barrel from end to end.

A represents a tube or barrel of any suitable or desired material, such aspis commonlv used for this pumpose.- Such barrels may he "ournaled at. the ends, or preferably mounted upon rollers 2, and suitable rings or tracks on the barrel which rest upon the rollers. Power is applied. to the shaft, of one of these rollers, or througho counters shaft, so that the revolution of the rollers will slowly rotote the barrel, Any suitable or desired feeding mechanism may he em, ployed so that. the ore already pulverized by stamp lmtlvrirs or nulls used for the preliminary reduction, will he led into the tube or barrel ut any desired rate.

ln my invention l employ plates 3, which are here shown as being reclzmgrulur in shape, and having the. opposite surfaces curved, with a convexity which corresponds with the interior mlrvulurc. or concavity of the barrel. l prefer lo make the uxls of convexity diagonal from one angle to the other of the plates, the other two angles transverse thereto, and in thi': line of the circunlfcrem-e of the inlcrior of the barrel. Those plates thus present a large grinding surface which is prosenl'ml toward the hottom of the barrel, and by their peculiar shape they provide for a very extensive grinding surface, and at the some time they ivill remain substantially in line with each tl1er. and not become misplaced. The pull) hissing between them and the interior of the c ,'lin(lers. or the shoes with which it may he lined, will he rupidl redured lo a very lino pulp, such as is required. for the proper treatnwnt by, what is known as the cyanidinir process.

Screens are located at the discharge end of "the apparatus, such screens having the desired lll1(-il(-f-.i5, and the operation need not be eil'ected in charges, but may he made continuous, the pulp being supplied through. the feed end of the apparatus in proportion to the rapidity of its discharge from the op posilze end.

- By making the shoes with double convex faces, it will he seen thatthey may be rcversed so that either side may present the grinding surface; and by reason of the length of the cylindrical convexity, the shoes will maintain themselves in proper relation 7 with each other, and Will not be inclined to over-ride or get out of place.

Having thus described my invention, What I claim and desire to secure by Letters Patent is An'improved grinding barrel having in combination, a. revolubly mounted barrel ofcylindrical form and shoes operable Within the barrel, said shoes being of substantially rectangular outline and having their oppo-- site surfaces curved With a convexity which correspoiids with the interiorcurvature or concavity of the barrel, the axis of convexity being from one angle to the other of the my hand in presence of twcfsuberileing wit shees, and the other two angles bemg transmesses. v?

' verse thereto and in the line of the eireumference of the interior of the barrel, said V shoes being reversible to present either side Witnesses e as e grindmg surface. FRANK L. OWEN, v

In testimony whereof I have hereunto set CHARLES A. PEN rxnLl). 

